24 
PHYSIOLOGY: S. HATAI 
the starved animal. This shows that the nitrogen also has been consumed 
during the period of starvation. 
5. The nitrogen contents for the different parts of the body are similar 
in their relations to those found in the normal Cassiopea. 
6. The loss in weight of the different parts is of such a character that their 
proportions in the starved remain similar to those in the normal Cassiopea. 
From his data Mayer concluded that the percentage of nitrogen in 
the solids is independent of the period of starvation, and is practically 
identical with that obtained from the non-starved Cassiopea. I have 
however found, as stated above, that starvation tends to increase not 
only the percentage of nitrogen in the solids, but also that the absolute 
amount of nitrogen shows an increase when the starved Cassiopeas were 
compared with the normals having the same body weight. 
The discrepancy between the conclusions drawn by Mayer and by 
myself is I believe due to the fact that Mayer's observations were limited 
to the larger Cassiopeas (body weights over 100 grams) in which the 
percentage of nitrogen in the solids shows little variation following the 
large variations of the body weight, while the variations in the nitrogen 
are quite noticeable in the Cassiopeas of smaller size. I may add here 
that the data given by Mayer in his table 2, show also a slight indication 
of a difference in the nitrogen content between the normal and starved 
Cassiopeas. 
I have applied Mayer's law for the loss of weight in starving Cassio- 
peas to my own data, and found a satisfactory agreement between the 
observed and calculated values by the formula 
F = 83.58 (1-0.05)*-^ 
where Y represents body weight and X the number of days of starvation. 
My formula differs from that of Mayer in that I give the exponent as 
{x - 1) while Mayer gives it simply as x. He did not however con- 
sider the loss during the first day as being due to starvation, for during 
this time considerable quantities of undigested food and slime are dis- 
charged and the loss is thus excessive and irregular. Hence our formulas 
are in essential accord one with the other, both applying after the 
medusa has discharged its undigested food and its gastric cavity is 
empty. The lower body weight obtained, as compared with that cal- 
culated at an earlier period of starvation, was probably due to the fre- 
quent handling of the animal in order to determine the body weight 
daily. 
A more detailed paper will appear in a volume of Researches from the 
Department of Marine Biology of the Carnegie Institution now in 
preparation. 
